United Kingdom
September 27, 2024
Photograph: Daniel Draghici / Alamy
During the past year, the NFU has brought together a Wheat Protein Roundtable of industry colleagues to discuss the sustainability challenges of growing milling wheat in the UK. NFU senior combinable crops policy specialist Luke Cox reports.
The NFU, AHDB, AIC, UK Flour Millers, British Society of Plant Breeders, NIAB and Defra have all been involved in the discussions, which have been driven by the volatility of nitrogen prices, set against the protein requirements of the milling sector and breadmaking end users.
Following the fertiliser crisis, where costs spiralled out of control, growers were forced to make difficult decisions about the amount of N fertiliser they could afford to apply to milling crops.
A recent NFU intentions survey confirms this, showing that growers are removing risk from their farm business by reducing fertiliser use. And this might involve moving away from growing milling wheat for bread.
Supply chain demands
At the same time, there are rapidly increasing demands on our sustainability as a food supply chain, complicated by the fact that that the direction from government, policy and consumers does not always align.
For the roundtable, industry policy on milling wheat must encourage investment into meeting the needs of the whole supply chain – with enough focus on producing food, as well as environmental sustainability.
The UK breadmaking market uses four million tonnes of domestic wheat combined with a million tonnes of imports to produce four million tonnes of flour each year.
The demand for milling wheat is growing, but pressure on arable land use is also increasing.
“The solution to sustainability is not to offshore our output.”
NFU senior combinable crops policy specialist Luke Cox
When it comes to risk versus reward, that pressure is ratcheted up because extreme weather events can have a large impact on protein quality and its functionality for the downstream supply chain (as well as quantity).
Ultimately, grain quality is not always fully within the farmer’s control.
Could we just shift the target?
The sector is committed to 13% protein content in milling wheat for a number of reasons. Demand, which must be met by farmers and millers, comes from further down the supply chain.
Gluten from protein is required to hold the bread together, and this only increases in importance when products such as seeds and fruit, which consumers enjoy, are added to a traditional white loaf.
Protein is fundamental to the bread-making process and the bakers know their minimum requirements to make a consistent loaf, especially when automated processes are used.
Protein content, then, is a proxy for supply chain functionality and the 13% is far from arbitrary. The requirement is actually for protein quality, but it is currently not possible to test this on intake in an effective manner; there simply isn’t a system to do this and it would likely be very challenging and expensive to design and implement.
While millers might prefer to buy on functionality, time constraints at intake mean it is protein quantity that is tested. Millers are prepared to buy lower protein grains in years when it has been difficult to reach 13% content, and they quite often take fallbacks down to 12%. But that shortfall must be replaced to create a product of the demanded specification, and to do that high-protein milling wheat from other countries such as Canada and Germany is blended in.
Hypothetically, if the standard protein specification for UK milling wheat were lowered from 13% to 12% to reduce fertiliser requirements, there would be no margin for error to accept fallbacks.
Furthermore, imports of high-protein breadmaking wheat would increase to maintain flour functionality, reducing both the demand for domestic breadmaking wheat and the premium paid, to account for the elevated costs of importing more high-protein wheat.
Import competition
The solution to sustainability is not to offshore our output.
UK growers are recognised to produce some of the highest quality and most sustainable food in the world, supported by a climate which is well suited to growing crops such as wheat.
When high-protein wheat is imported from other countries, its sustainability attributes are not measured and do not necessarily reach the same levels.
This puts added pressure on UK growers to farm in a certain way while trying to compete with imports produced to a different standard.
What about varieties?
A third of the modern varieties currently available to growers require more than 280kg N/ha to reach milling specification, and a further quarter require more than 300kg N/ha.
The general understanding is that, on average, an additional 40kg N/ha increases grain protein by 0.5%, an additional 80kg N/ha increases grain protein by 1.0%, and an additional 120kg N/ha increases grain protein by 1.3%.
However, in AHDB trials some varieties actually performed better at lower nitrogen applications than at higher applications.
Plant breeders are heavily invested in researching new varieties, and current trials are looking at options to further improve the offer to farmers, with the hope that new varieties can be brought to market that will reduce the risk associated with growing milling wheat.
The focus is on those that sit above the ‘grain protein deviation line’ – a direct measure of how efficiently a plant is converting nitrogen into protein content as well as yield. Varieties with better nitrogen use efficiency are already in development and this is a key area growers would like to be able to consider when making planting choices.
Research suggests that reaching the required grain protein quantity from lower nitrogen applications could come from more efficient translocation of N into the grain and increased proportions of total glutenin, which results in greater dough elasticity.
While precision breeding should not be considered a silver bullet here, some research with wild grass genes has hinted at promising opportunities. The most effective boost to protein to have been shown so far has come from using foliar urea at the milky-ripe stage of development.
There is no detrimental impact on baking quality when foliar urea is used instead of ammonium nitrate, and, in fact, foliar urea has been shown to deliver a greater increase in grain protein content.
Measuring N on farm
Assessing the nitrogen status of a crop accurately to allow targeted fertiliser decisions is often difficult.
To make the best prediction of grain protein content ahead of a harvest, growers should use the wheat ears rather than the whole plant material to conduct the assessment, and use dried material rather than plants straight from the field.
Plant nitrogen can be analysed using near-infrared assessments or the Dumas method to enable quick fertiliser decisions, using established maximum grain protein forecasting to justify whether a foliar application of urea is a worthwhile investment.
The take-homes
The latest roundtable concluded with the understanding that it is in the interests of the whole milling wheat supply chain to deliver innovation and investment into producing sustainable milling wheat.
While there has been various research on measures which could reduce the nitrogen requirement for a crop, the fact remains that growers in the UK are still heavily reliant on N to meet the specifications demanded by the supply chain.
Meanwhile, the demand for environmental data will only increase, and there may well be a time when the value that can be derived from a more sustainable feed wheat crop exceeds the value of a less sustainable milling crop.
This means it is vital that industry leaders continue to work together to deliver the best suite of options for growers, to ensure they can remain a strong primary producer for the UK milling sector.
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